stain removal

[poolhelp101]

tell me what i done wrong and how to fix. i had stains on my pool and i used the asboric acid method to remove. chlorine was at zero when i done the asboric acid. the stains vanished just as instructed. the pool was perfect. the next day i added bleach to start to bring the chlorine back up and everything still good. two days later, today, i notice the pool started to have a green tint. i added polyquat, and more bleach as the chlorine was showing very little. one thing i did forget to do is add metal out. is this what i done wrong? should i add metal out now?? the only other thing i done right after i used the asboric acid was to turn on my heater. did that have an effect on it? i have a 21,000 gallon inground, sand filter. please tell me what steps to take to get the pool back on track. thanks.